1. Field of the Invention
The present invention relates generally to a method and a system for controlling an air intake of a fuel cell vehicle to maintain a particular amount of air flow preemptively to supply more stable output power when output power of the fuel cell increases.
2. Description of the Related Art
For commercialization of a fuel cell vehicle, it is important to maintain substantially stable output power performance and durability of the fuel cell that corresponds to that of an engine of an internal combustion engine vehicle. To increase output power stability, a particular amount of air flow for target output power should be stably supplied. Since air supply using a blower is substantially slow, durability degradation and output power performance reduction may occur due to slow air supply when output power increases without maintaining a particular amount of air flow. Therefore a particular amount of air flow is required to be maintained preemptively (e.g., prior to the output power increases to prevent durability degradation and output power performance reduction). When supplying air preemptively, an excessive air supply should be avoided which may result in dry-out of the fuel cell and durability degradation.
Consequently, the fuel cell vehicle maintains a particular amount of air flow preemptively and thereby increases output power of the fuel cell more stably and ensures acceleration performance of the vehicle. Additionally, the fuel cell vehicle improves durability by avoiding a shortage of air or an excessive air supply to the fuel cell by optimization of the air supply.
In the related art, a fuel cell hybrid vehicle equipped with an additional battery, supplies air using an estimated current value of the fuel cell, which is obtained by subtracting a current value assisted by a battery from a current value required by a motor. The current value required by the motor is calculated using a motor output map based on a motor torque command value. When a motor requirement map is not accurate due to a variation of motor products, an excessive air supply or a shortage of air may occur. Such a situation may occur in an induction motor. In particular, in the induction motor, as output power is changed with a temperature of a rotor, it may be difficult to obtain an accurate motor map. The invention based on the amount of power required by a stack may not satisfy acceleration performance of a vehicle not considering the slow speed of air supply by a blower.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.